Muffler



MUFFLER Filed Feb. 2l, 1934 INVENTOR.

ATTORNEYS.

Patented Mar. 31, 1936 UNITED STATES PATENT OFFICE MUFFLER Winthrop T. Scarritt, Utica, N. Y. Application February 2.1,v 1934, Serial No. 712,362

2 Claims. (Cl. 137-160) 'I'his invention relates to certain improvements in mulers or silencers particularly designed for use in connection with the exhaust of internal combustion motors in order to effectively deaden 5 the sound waves resulting from the explosions without the setting up of detrimental back pressure.

The invention provides an improved muiiler or silencer of the indicated character embodying means which is so constructed and arranged as to deflect and break up the sound waves into a plurality of whorls or eddy streams which interact to nullify the explosive peaks of the sound waves.

The invention more particularly resides in a muiiler or silencer which is so constructed as to provide a main passage and a sound deadening chamber with ports establishing communication therebetween, which ports are so constructed and located as to cause the deflection and breaking up 2G of the sound waves into a plurality of streams which pass through the ports and form interacting whorls or eddies in the deadening chamber which function to deaden the explosive peaks of the sound waves.

'I'he invention further contemplates a muler or silencer in which the gases and sound waves traveling at high velocity through a restricted passage are directed in the form of streams or whorls through ports into an enlarged deadening chamber where the streams or whorls expand and interact upon each other to effectively deaden the sound waves.

The invention further comprehends a muler or silencer provided with inner and outer tubular casings defining a passage for the gases and sound waves, and an expansion and deadening chamber, and with means in the inner casing extending into the passage for deecting and causing the gases and sound Waves to pass from said passage into the chamber in a plurality or whorls or streams.

The invention further provides a muiller which is relatively simple in construction, is light in weight and may be produced at low cost and which is emcient for its intended purpose without the setting up oi detrimental back pressure.

With the above recited and other objects in view, reference is made to the following specication and accompanying drawing in which there is set forth ltwo forms of the invention.

In the drawing:

Fig. 1 is a longitudinal vertical sectional view of a. mulller embodying the invention.

Fig. 2 is a, cross sectional view taken approximately on the line 2-2 of Fig. 1.

, desired manner, and provided with outwardly 10 projecting tubular bosses or collars I3 for respectively connecting the muffler to the exhaust and tail pipes and providing an inlet and outlet for the mufer. The shell l0 may be of any desired cross sectional configuration and may be 15 of sheet metal or cast or otherwise formed. In the instant embodiment, the shell I0 is shown as of .circular cross sectional formation and the end heads II and I2 are provided with marginal flanges I4 which are welded or otherwise secured 20 within the opposite ends of the casing I0.

The casing I0 is subdivided into longitudinally extending compartments A and, B by means of a longitudinally disposed tubular shell I5 which is located intermediate the ends of the casing 25 I0, preferably concentric therewith, and which is supported by the casing III in any desired manner. As illustrated in Figs. 1 and 2, the shell I5 is connected to the casing I0 by frustoconical frames I6 and Il having their larger 30 ends disposed towards the muffler inlet and formed with outer marginal fianges I8 welded or otherwisesecured to the inner periphery of the casing I0. The foremost frame I6 is provided at its inner edge with a rearwardly directed 35 tubular boss I9 tted over the forward end of the shell I5 and welded or otherwise secured thereto, while the rearmost frame I'I is also formed with a rearwardly directed tubular boss 2|] at its inner edge which snugly ts the rear 40` end of the shell I5 but which is unsecured thereto in order to permit of relative sliding movement of the shell I5 with respect thereto so as t0 compensate for contraction and expansion.

In the embodiment of the invention illus- 45 trated, the compartment A constitutes a main passage for the gases and the sound waves, while the compartment B functions primarily as a sound wave expansion and deadening chamber. The shell I5 is provided with a plurality of lon- 50 gitudinally spaced sets of inwardly directed louvers 2|, the louvers in each set being spaced circumferentially of the shell and alternate sets, if desired, being disposed in staggered relation, as shown. The louvers 2l are so fashioned as vto provide scoop-shaped projections having forwardly disposed inlet ends or ports 22 which intercept the gases and sound waves as they pass through the compartment or passage A and direety the same into theexpansion and deadening chamber B in the form of streams or whorls, which streams or whorls expand and interact to nullify the explosive peaks of the sound waves. The louvers 2i may be of any desired form, but as illustrated, the same are produced by slitting the shell I5 circumferentially and pressing 1nwardly the portions of the shell lying in the rear of each slit into the form of scoop-like projections.

The frames I6 and Il are each provided with annularly spaced rearwardly directed louvers 23 embodiment, forwardly of the shell and one rearwardly thereof, which are similar in construction to the frusto-conical frame I5 and which have their outer marginal flanges 26 welded or otherwise secured to the inner periphery` of the casing Id. The bales 25 thus subdivide the casing forwardly of the shell I 5 and rearwardly thereof, into longitudinally spaced compartments or expansion chambers each with a restricted passage 2l formed by the tubular boss 28 establishing communication therebetween. l

In the form of the invention illustrated in Figs. 3 and 4 of the drawing, a tubular shell 25 extends longitudinally of the casing 30 between the end heads SI and 32, and has its forward end welded or otherwise secured in the tubular boss or collar 33 of the end head 3 I, while its rear end snugly ts the tubular boss or collar 3&3 of the end head 32, but which is unsecured therein to admit of relative sliding movement so as to compensate for contraction or expansion of the parts. The shell 29 thus subdivides the casing into longitudinally extending compartments C and D, the compartment C constituting a main passage for the gases and sound waves, while the compartment D functions as a sound wave expansion and deadening chamber.

'I'he shell 29 is provided with a plurality of Iongitudinally spaced sets of inwardly directed louvers 35 which may be of any desired form, but which, as illustrated, are similar in construction to the louvers 2| and, if desired, are arranged with alternate sets in staggered relation. The louvers 35 function to intercept the gases and sound waves passing through the main passage C and to deiiect the same into the expansion and deadening chamber D in the form of streams or whorls which interact to nullify or blanket the peaks of the sound waves.

What is claimed is:

1. A silencer of the character described including an elongated casing, a shell within said casing and a frame adjacent each end of said shell securing the same in spaced relation within the casing to provide achamber between the shell and casing, said frame having rearwardly and inwardly flared conical walls with annularly spaced apertured portions opening into and out of said chamber respectively, and rearwardly directed inwardly inclined radial louvers'projecting from the edges of the apertured portions to overlie the apertures respectively, and said shell having a plurality of longitudinally spaced sets of inwardly struck forwardly projecting louvers dening ports and sound wave derlecting means for intercepting and deflecting the sound waves within said shell to form a plurality of streams as they pass through said ports into said chamber.

2. A silencer of the character described including an elongated casing, a shell Within said. casing and a frame adjacent each end of said shell securing the same in spaced relation within the casing to provide a chamber between the shell and casing, said frame having rearwardly and inwardly flared conical walls with annularly spaced apertured portions opening into and out of said chamber respectively, and rearwardly directed inwardly inclined radial louvers projecting from the edges of the apertured portions to overlie the apertures respectively and said shell having a plurality of longitudinally spaced sets of semi-elliptical apertures opening into the said chamber and inwardly struck forwardly projecting louvers of longitudinal and transverse concavo-convex form secured about the curved edges of the aperture portions respectively to define ports and sound wave deiiecting means for intercepting, and deecting the sound waves within said shell to form a plurality of streams as they pass through said ports into said chamber.

WINTHROP .T. SCARRI'I'I. 

